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Getting Started

Unit Testing for Ansible Collections

The pytest-ansible plugin allows ansible collection's unit tests to be run with only pytest. It offers a focused approach to testing individual Ansible modules. With this plugin, you can write and execute unit tests specifically for Ansible modules, ensuring the accuracy and reliability of your module code. This is particularly useful for verifying the correctness of module behavior in isolation.

To use pytest-ansible, follow these steps:

  1. Install the plugin using [pip]:
pip install pytest-ansible
  1. Ensure you have Python 3.10 or greater, ansible-core, and pytest installed.

  2. Depending on your preferred directory structure, you can clone collections into the appropriate paths.

  3. Collection Tree Approach: The preferred approach is to clone the collections being developed into it's proper collection tree path. This eliminates the need for any symlinks and other collections being developed can be cloned into the same tree structure.

    git clone <repo> collections/ansible_collections/<namespace>/<name>
    

    Note: Run pytest in the root of the collection directory, adjacent to the collection's galaxy.yml file.

  4. Shallow Tree Approach:

    git clone <repo>
    

    Notes:

    • Run pytest in the root of the collection directory, adjacent to the collection's galaxy.yml file.
    • A collections directory will be created in the repository directory, and collection content will be linked into it.
  5. Execute the unit tests using pytest: pytest tests

Help

The following may be added to the collections' pyproject.toml file to limit warnings and set the default path for the collection's tests

[tool.pytest.ini_options]
testpaths = [
    "tests",
]
filterwarnings = [
    'ignore:AnsibleCollectionFinder has already been configured',
]

Information from the galaxy.yml file is used to build the collections directory structure and link the contents. The galaxy.yml file should reflect the correct collection namespace and name.

One way to detect issues without running the tests is to run:

pytest --collect-only

The follow errors may be seen:

E   ModuleNotFoundError: No module named 'ansible_collections'
  • Check the galaxy.yml file for an accurate namespace and name
  • Ensure pytest is being run from the collection's root directory, adjacent to the galaxy.yml
HINT: remove __pycache__ / .pyc files and/or use a unique basename for your test file modules

Molecule Scenario Integration

This functionality assists in running Molecule scenarios using pytest. It enables pytest discovery of all molecule.yml files inside the codebase and runs them as pytest tests. It allows you to include Molecule scenarios as part of your pytest test suite, allowing you to thoroughly test your Ansible roles and playbooks across different scenarios and environments.

Running molecule scenarios using pytest

Molecule scenarios can be tested using 2 different methods if molecule is installed.

Recommended:

Add a test_integration.py file to the tests/integration directory of the ansible collection:

"""Tests for molecule scenarios."""
from __future__ import absolute_import, division, print_function

from pytest_ansible.molecule import MoleculeScenario


def test_integration(molecule_scenario: MoleculeScenario) -> None:
    """Run molecule for each scenario.

    :param molecule_scenario: The molecule scenario object
    """
    proc = molecule_scenario.test()
    assert proc.returncode == 0

The molecule_scenario fixture provides parameterized molecule scenarios discovered in the collection's extensions/molecule directory, as well as other directories within the collection.

molecule test -s <scenario> will be run for each scenario and a completed subprocess returned from the test() call.